Callback Service

Undefined

The world's leading PTR-MS company

Providing ultra-sensitive solutions for real-time trace gas analysis since 1998

Navigation

You are here

Scientific Articles - PTR-MS Bibliography

Welcome to the new IONICON scientific articles database!

Publications

Found 17 results
Title [ Year(Asc)]
Filters: Author is Herbig, Jens  [Clear All Filters]
2015
[1655] Materic, D., M. Lanza, P. Sulzer, J. Herbig, D. Bruhn, C. Turner, N. Mason, and V. Gauci, "Monoterpene separation by coupling proton transfer reaction time-of-flight mass spectrometry with fastGC", Analytical and Bioanalytical Chemistry, Aug, 2015.
Link: http://dx.doi.org/10.1007/s00216-015-8942-5
Abstract
<p>Proton transfer reaction mass spectrometry (PTR-MS) is a well-established technique for real-time analysis of volatile organic compounds (VOCs). Although it is extremely sensitive (with sensitivities of up to 4500 cps/ppbv, limits of detection &lt;1 pptv and the response times of approximately 100 ms), the selectivity of PTR-MS is still somewhat limited, as isomers cannot be separated. Recently, selectivity-enhancing measures, such as manipulation of drift tube parameters (reduced electric field strength) and using primary ions other than H3O+, such as NO+ and O2 +, have been introduced. However, monoterpenes, which belong to the most important plant VOCs, still cannot be distinguished so more traditional technologies, such as gas chromatography mass spectrometry (GC-MS), have to be utilised. GC-MS is very time consuming (up to 1 h) and cannot be used for real-time analysis. Here, we introduce a sensitive, near-to-real-time method for plant monoterpene research&mdash;PTR-MS coupled with fastGC. We successfully separated and identified six of the most abundant monoterpenes in plant studies (α- and β-pinenes, limonene, 3-carene, camphene and myrcene) in less than 80 s, using both standards and conifer branch enclosures (Norway spruce, Scots pine and black pine). Five monoterpenes usually present in Norway spruce samples with a high abundance were separated even when the compound concentrations were diluted to 20 ppbv. Thus, fastGC-PTR-ToF-MS was shown to be an adequate one-instrument solution for plant monoterpene research.</p>
[1711] Materic, D., M. Lanza, P. Sulzer, J. Herbig, D. Bruhn, C. Turner, N. Mason, and V. Gauci, "Monoterpene separation by coupling proton transfer reaction time-of-flight mass spectrometry with fastGC.", Anal Bioanal Chem, vol. 407, pp. 7757–7763, Oct, 2015.
Link: http://dx.doi.org/10.1007/s00216-015-8942-5
Abstract
<p>Proton transfer reaction mass spectrometry (PTR-MS) is a well-established technique for real-time analysis of volatile organic compounds (VOCs). Although it is extremely sensitive (with sensitivities of up to 4500 cps/ppbv, limits of detection &lt;1 pptv and the response times of approximately 100 ms), the selectivity of PTR-MS is still somewhat limited, as isomers cannot be separated. Recently, selectivity-enhancing measures, such as manipulation of drift tube parameters (reduced electric field strength) and using primary ions other than H3O(+), such as NO(+) and O2 (+), have been introduced. However, monoterpenes, which belong to the most important plant VOCs, still cannot be distinguished so more traditional technologies, such as gas chromatography mass spectrometry (GC-MS), have to be utilised. GC-MS is very time consuming (up to 1 h) and cannot be used for real-time analysis. Here, we introduce a sensitive, near-to-real-time method for plant monoterpene research-PTR-MS coupled with fastGC. We successfully separated and identified six of the most abundant monoterpenes in plant studies (α- and β-pinenes, limonene, 3-carene, camphene and myrcene) in less than 80 s, using both standards and conifer branch enclosures (Norway spruce, Scots pine and black pine). Five monoterpenes usually present in Norway spruce samples with a high abundance were separated even when the compound concentrations were diluted to 20 ppbv. Thus, fastGC-PTR-ToF-MS was shown to be an adequate one-instrument solution for plant monoterpene research.</p>
2014
[1564] Smith, D., P. Spanel, J. Herbig, and J. Beauchamp, "Mass spectrometry for real-time quantitative breath analysis", Journal of Breath Research, vol. 8, pp. 027101, Mar, 2014.
Link: http://dx.doi.org/10.1088/1752-7155/8/2/027101
Abstract
<p>Breath analysis research is being successfully pursued using a variety of analytical methods, prominent amongst which are gas chromatography with mass spectrometry, GC-MS, ion mobility spectrometry, IMS, and the fast flow and flow-drift tube techniques called selected ion flow tube mass spectrometry, SIFT-MS, and proton transfer reaction mass spectrometry, PTR-MS. In this paper the case is made for real-time breath analysis by obviating sample collection into bags or onto traps that can suffer from partial degradation of breath metabolites or the introduction of impurities. Real-time analysis of a broad range of volatile chemical compounds can be best achieved using SIFT-MS and PTR-MS, which are sufficiently sensitive and rapid to allow the simultaneous analyses of several trace gas metabolites in single breath exhalations. The basic principles and the ion chemistry that underpin these two analytical techniques are briefly described and the differences between them, including their respective strengths and weaknesses, are revealed, especially with reference to the analysis of the complex matrix that is exhaled breath. A recent innovation is described that combines time-of-flight mass spectrometry with the proton transfer flow-drift tube reactor, PTR-TOFMS, which provides greater resolution in the analytical mass spectrometer and allows separation of protonated isobaric molecules. Examples are presented of some recent data that well illustrate the quality and real-time feature of SIFT-MS and PTR-MS for the analysis of exhaled breath for physiological/biochemical/pharmacokinetics studies and for the identification and quantification of biomarkers relating to specific disease states.</p>
[1602] Smith, D., P. Spanel, J. Herbig, and J. Beauchamp, "Mass spectrometry for real-time quantitative breath analysis.", J Breath Res, vol. 8, pp. 027101, Jun, 2014.
Link: http://dx.doi.org/10.1088/1752-7155/8/2/027101
Abstract
<p>Breath analysis research is being successfully pursued using a variety of analytical methods, prominent amongst which are gas chromatography with mass spectrometry, GC-MS, ion mobility spectrometry, IMS, and the fast flow and flow-drift tube techniques called selected ion flow tube mass spectrometry, SIFT-MS, and proton transfer reaction mass spectrometry, PTR-MS. In this paper the case is made for real-time breath analysis by obviating sample collection into bags or onto traps that can suffer from partial degradation of breath metabolites or the introduction of impurities. Real-time analysis of a broad range of volatile chemical compounds can be best achieved using SIFT-MS and PTR-MS, which are sufficiently sensitive and rapid to allow the simultaneous analyses of several trace gas metabolites in single breath exhalations. The basic principles and the ion chemistry that underpin these two analytical techniques are briefly described and the differences between them, including their respective strengths and weaknesses, are revealed, especially with reference to the analysis of the complex matrix that is exhaled breath. A recent innovation is described that combines time-of-flight mass spectrometry with the proton transfer flow-drift tube reactor, PTR-TOFMS, which provides greater resolution in the analytical mass spectrometer and allows separation of protonated isobaric molecules. Examples are presented of some recent data that well illustrate the quality and real-time feature of SIFT-MS and PTR-MS for the analysis of exhaled breath for physiological/biochemical/pharmacokinetics studies and for the identification and quantification of biomarkers relating to specific disease states.</p>
2013
[Kohl2013b] Kohl, I., J. Beauchamp, F. Cakar-Beck, J. Herbig, J.. Dunkl, O. Tietje, M. Tiefenthaler, C. Boesmueller, A. Wisthaler, M. Breitenlechner, et al., "First observation of a potential non-invasive breath gas biomarker for kidney function.", J Breath Res, vol. 7, no. 1: Ionimed Analytik GmbH, Eduard Bodem Gasse 3, A-6020 Innsbruck, Austria., pp. 017110, Mar, 2013.
Link: http://dx.doi.org/10.1088/1752-7155/7/1/017110
Abstract
We report on the search for low molecular weight molecules-possibly accumulated in the bloodstream and body-in the exhaled breath of uremic patients with kidney malfunction. We performed non-invasive analysis of the breath gas of 96 patients shortly before and several times after kidney transplantation using proton-transfer-reaction mass spectrometry (PTR-MS), a very sensitive technique for detecting trace amounts of volatile organic compounds. A total of 642 individual breath analyses which included at least 41 different chemical components were carried out. Correlation analysis revealed one particular breath component with a molecular mass of 114 u (unified atomic mass units) that clearly correlated with blood serum creatinine, which is the currently accepted marker for assessing the function of the kidney. In particular, daily urine production showed good correlation with the identified breath marker. An independent set of seven samples taken from three patients at the onset of dialysis and three controls with normal kidney function confirmed a significant difference in concentration between patients and controls for a compound with a molecular mass of 114.1035 u using high mass resolving proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOF-MS). A chemical composition of CHO was derived for the respective component. Fragmentation experiments on the same samples using proton-transfer-reaction triple-quadrupole tandem mass spectrometry (PTR-QqQ-MS) suggested that this breath marker is a C-ketone or a branched C-aldehyde. Non-invasive real-time monitoring of the kidney function via this breath marker could be a possible future procedure in the clinical setting.
[Fischer2013a] Fischer, L., A. Klinger, J. Herbig, K. Winkler, R. Gutmann, and A. Hansel, "The LCU: Versatile Trace Gas Calibration", 6th International PTR-MS Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, pp. 192, 2013.
Link: http://www.ionicon.com/sites/default/files/uploads/doc/contributions_ptr_ms_Conference_6.pdf
[Fischer2013] Fischer, L., V. Ruzsanyi, K. Winkler, R. Gutmann, A. Hansel, and J. Herbig, "Micro-Capillary-Column PTR-TOF", 6th International PTR-MS Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, pp. 162, 2013.
Link: http://www.ionicon.com/sites/default/files/uploads/doc/contributions_ptr_ms_Conference_6.pdf
[1445] Ruzsanyi, V., L. Fischer, J. Herbig, C. Ager, and A. Amann, "Multi-capillary-column proton-transfer-reaction time-of-flight mass spectrometry.", J Chromatogr A, vol. 1316, pp. 112–118, Nov, 2013.
Link: http://dx.doi.org/10.1016/j.chroma.2013.09.072
Abstract
<p>Proton-transfer-reaction time-of-flight mass-spectrometry (PTR-TOFMS) exhibits high selectivity with a resolution of around 5000m/Δm. While isobars can be separated with this resolution, discrimination of isomeric compounds is usually not possible. The coupling of a multi-capillary column (MCC) with a PTR-TOFMS overcomes these problems as demonstrated in this paper for the ketone isomers 3-heptanone and 2-methyl-3-hexanone and for different aldehydes. Moreover, fragmentation of compounds can be studied in detail which might even improve the identification. LODs for compounds tested are in the range of low ppbv and peak positions of the respective separated substances show good repeatability (RSD of the peak positions &lt;3.2%). Due to its special characteristics, such as isothermal operation, compact size, the MCC setup is suitable to be installed inside the instrument and the overall retention time for a complete spectrum is only a few minutes: this allows near real-time measurements in the optional MCC mode. In contrast to other methods that yield additional separation, such as the use of pre-cursor ions other than H3O(+), this method yields additional information without increasing complexity.</p>
[Winkler2013] Winkler, K., J. Herbig, and I. Kohl, "Real-time metabolic monitoring with proton transfer reaction mass spectrometry", Journal of breath research, vol. 7, no. 3: IOP Publishing, pp. 036006, 2013.
Link: http://iopscience.iop.org/1752-7163/7/3/036006
Abstract
<p><span style="color: rgb(0, 0, 0); font-family: Arial, Helvetica, Verdana, sans-serif; font-size: 12px; line-height: 16.1875px; background-color: rgb(255, 255, 255);">We analysed the time evolution of several volatile organic compounds formed by the catabolism of ingested isotope-labelled ethanol using real-time breath gas analysis with proton-transfer-reaction mass spectrometry. Isotope labelling allowed distinguishing the emerging volatile metabolites from their naturally occurring, highly abundant counterparts in the human breath. Due to an extremely low detection limit of the employed technologies in the parts per trillion per volume range, it was possible to detect the emerging metabolic products in exhaled breath within ~10&nbsp;min after oral ingestion of isotope-labelled ethanol. We observed that ethanol was in part transformed into deuterated acetone and isoprene, reflecting the different fates of activated acetic acid (acetyl-coenzyme A), formed in ethanol metabolism. Using ethanol as a model clearly demonstrated the value of the here presented technique for the search for volatile markers for metabolic disorders in the exhaled breath and its potential usefulness in the diagnosis and monitoring of such diseases.</span></p>
2012
[Luchner2012] Luchner, M., R. Gutmann, K. Bayer, J. Dunkl, A. Hansel, J. Herbig, W. Singer, F. Strobl, K. Winkler, and G. Striedner, "Implementation of proton transfer reaction-mass spectrometry (PTR-MS) for advanced bioprocess monitoring.", Biotechnol Bioeng, vol. 109, no. 12: ACIB GmbH, Muthgasse 11, A-1190 Vienna, Austria., pp. 3059–3069, Dec, 2012.
Link: http://dx.doi.org/10.1002/bit.24579
Abstract
We report on the implementation of proton transfer reaction-mass spectrometry (PTR-MS) technology for on-line monitoring of volatile organic compounds (VOCs) in the off-gas of bioreactors. The main part of the work was focused on the development of an interface between the bioreactor and an analyzer suitable for continuous sampling of VOCs emanating from the bioprocess. The permanently heated sampling line with an inert surface avoids condensation and interaction of volatiles during transfer to the PTR-MS. The interface is equipped with a sterile sinter filter unit directly connected to the bioreactor headspace, a condensate trap, and a series of valves allowing for dilution of the headspace gas, in-process calibration, and multiport operation. To assess the aptitude of the entire system, a case study was conducted comprising three identical cultivations with a recombinant E. coli strain, and the volatiles produced in the course of the experiments were monitored with the PTR-MS. The high reproducibility of the measurements proved that the established sampling interface allows for reproducible transfer of volatiles from the headspace to the PTR-MS analyzer. The set of volatile compounds monitored comprises metabolites of different pathways with diverse functions in cell physiology but also volatiles from the process matrix. The trends of individual compounds showed diverse patterns. The recorded signal levels covered a dynamic range of more than five orders of magnitude. It was possible to assign specific volatile compounds to distinctive events in the bioprocess. The presented results clearly show that PTR-MS was successfully implemented as a powerful bioprocess-monitoring tool and that access to volatiles emitted by the cells opens promising perspectives in terms of advanced process control.
2011
[Singer2011] Singer, W., J. Herbig, R. Gutmann, K. Winkler, I. Kohl, and A. Hansel, "Applications of PTR-MS in medicine and biotechnology", American Laboratory, vol. 43, no. 7: AMER LABORATORY-LABCOMPARE 30 CONTROLS DRIVE, SHELTON, CT 06484 USA, pp. 34–37, 2011.
Link: http://www.americanlaboratory.com/913-Technical-Articles/19001-Applications-of-PTR-MS-in-Medicine-and-Biotechnology/
Abstract
Proton transfer reaction-mass spectrometry (PTR-MS) is a well-established analytical tool for the measurement of volatile organic compounds (VOCs), and offers real-time detection and quantification of VOCs at trace concentrations. This paper focuses on the measurement of VOCs in biological systems. Both microorganisms and cells, e.g., in the human body, constantly produce a large variety of volatile organic metabolites. Analyzing VOCs in exhaled human breath reveals information about the status of the body. In a similar manner, monitoring the off-gas of fermentations in the biopharmaceutical industry allows microbial activity to be gauged. Undesired compounds (those that are harmful to the human body or impurities in biotechnical processes) can also be tracked in real time using the technique.
[Kohl2011] Kohl, I., J. Herbig, J. Beauchamp, J. Dunkl, O. Tietje, and A. Hansel, "Online breath analysis of volatile organic compounds with PTR-MS: a guanidino breath marker for the status of uremia and kidney transplant rejection diagnosis.", 4th International PTR-MS Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, pp. 251, 2011.
Link: http://www.ionicon.com/sites/default/files/uploads/doc/contributions_ptr_ms_Conference_5.pdf
2009
[Herbig2009a] Herbig, J., M. Müller, S. Schallhart, T. Titzmann, M. Graus, and A. Hansel, "On-line breath analysis with PTR-TOF.", J Breath Res, vol. 3, no. 2: Ionimed Analytik GmbH, Innsbruck, Austria., pp. 027004, Jun, 2009.
Link: http://dx.doi.org/10.1088/1752-7155/3/2/027004
Abstract
We report on on-line breath gas analysis with a new type of analytical instrument, which represents the next generation of proton-transfer-reaction mass spectrometers. This time-of-flight mass spectrometer in combination with the soft proton-transfer-reaction ionization (PTR-TOF) offers numerous advantages for the sensitive detection of volatile organic compounds and overcomes several limitations. First, a time-of-flight instrument allows for a measurement of a complete mass spectrum within a fraction of a second. Second, a high mass resolving power enables the separation of isobaric molecules and the identification of their chemical composition. We present the first on-line breath measurements with a PTR-TOF and demonstrate the advantages for on-line breath analysis. In combination with buffered end-tidal (BET) sampling, we obtain a complete mass spectrum up to 320 Th within one exhalation with a signal-to-noise ratio sufficient to measure down to pptv levels. We exploit the high mass resolving power to identify the main components in the breath composition of several healthy volunteers.
[Herbig2009] Herbig, J., M. Seger, I. Kohl, G. Mayramhof, T. Titzmann, A. Preinfalk, K. Winkler, J. Dunkl, B. Pfeifer, C. Baumgartner, et al., "Online breath sampling with PTR-MS - A setup for large screening studies", 4th International PTR-MS Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications, pp. 46, 2009.
Link: http://www.ionicon.com/sites/default/files/uploads/doc/contributions_ptr_ms_Conference_4.pdf
[Herbig2009b] Herbig, J., and A. Amann, "Proton transfer reaction-mass spectrometry applications in medical research.", J Breath Res, vol. 3, no. 2, pp. 020201, Jun, 2009.
Link: http://iopscience.iop.org/1752-7163/3/2/020201/
Abstract
Gathering information about a subject's physiological and pathophysiological condition from the `smell' of breath is an idea that dates back to antiquity. This intriguing concept of non-invasive diagnosis has been revitalized by `exhaled breath analysis' in recent decades. A main driving force was the development of sensitive and versatile gas-chromatographic and mass-spectrometric instruments for trace gas analysis. Ironically, only non-smelling constituents of breath, such as O(2), CO(2), H(2), and NO have so far been included in routine clinical breath analysis. The `smell' of human breath, on the other hand, arises through a combination of volatile organic compounds (VOCs) of which several hundred have been identified to date. Most of these volatiles are systemic and are released in the gas-exchange between blood and air in the alveoli. The concentration of these compounds in the alveolar breath is related to the respective concentrations in blood. Measuring VOCs in exhaled breath allows for screening of disease markers, studying the uptake and effect of medication (pharmacokinetics), or monitoring physiological processes. There is a range of requirements for instruments for the analysis of a complex matrix, such as human breath. Mass-spectrometric techniques are particularly well suited for this task since they offer the possibility of detecting a large variety of interesting compounds. A further requirement is the ability to measure accurately in the concentration range of breath VOCs, i.e. between parts-per-trillion (pptv) and parts-per-million (ppmv) range. In the mid 1990's proton transfer reaction-mass spectrometry (PTR-MS) was developed as a powerful and promising tool for the analysis of VOCs in gaseous media. Soon thereafter these instruments became commercially available to a still growing user community and have now become standard equipment in many fields including environmental research, food and flavour science, as well as life sciences. Their high sensitivity for VOCs with detection limits down to sub-pptv levels without pre-concentration and their highly linear signal response over seven orders of magnitude make PTR-MS instruments valuable tools for exhaled breath analysis. The `soft' chemical ionization process in PTR-MS largely avoids fragmentation, providing interpretable spectra without pre-separation. This is especially important for complex gas mixtures such as breath. Even more interesting, PTR-MS instruments analyse a gas sample in real-time and do not require any sample pre-treatment. This offers the possibility for online breath analysis with breath-to-breath resolution. This special issue on PTR-MS applications in medical research contains articles exploring different medical applications of PTR-MS. These applications include screening studies, where the breath composition of a large number of patients is investigated to, e.g., determine influences of demographic data on breath concentrations (Schwarz et al 2009 J. Breath Res. 3 027003). In online monitoring studies the breath of one subject is continuously measured, e.g., to study rapid changes in breath volatiles under physical exercise (King et al 2009 J. Breath Res. 3 027006). Other papers address more elementary breath research and discuss the interpretation of exhaled breath composition in the presence of fragmenting and overlapping compounds (Schwarz et al 2009 J. Breath Res. 3 027002), examine the different causes of variability in the measurement of breath samples (Thekedar et al 2009 J. Breath Res. 3 027007), and compare blood and breath concentrations directly (O'Hara et al 2009 J. Breath Res. 3 027005). Potential sources for breath markers are also explored, by analysing the head-space emissions from microbial culture samples (O'Hara and Mayhew 2009 J. Breath Res. 3 027001). Finally, a recent technological advancement in PTR-MS technology promises several advantages especially for breath gas analysis, which is demonstrated by on-line breath sampling with a PTR-time-of-flight (PTR-TOF) instrument (Herbig et al 2009 J. Breath Res. 3 027004).
[Kohl2009] Kohl, I., J. Herbig, J. Beauchamp, J. Dunkl, O. Tietje, and A. Hansel, "Proton-transfer-reaction mass spectrometry online analysis of volatile organic compounds in the exhaled breath: kidney transplant rejection diagnosis", CONFERENCE SERIES, pp. 251, 2009.
Link: http://www.ionicon.com/sites/default/files/uploads/doc/contributions_ptr_ms_Conference_4.pdf#page=251
2008
[Herbig2008] Herbig, J., T. Titzmann, J. Beauchamp, I. Kohl, and A. Hansel, "Buffered end-tidal (BET) sampling-a novel method for real-time breath-gas analysis.", J Breath Res, vol. 2, no. 3: Ionimed Analytik GmbH, Technikerstrasse 21a, A-6020 Innsbruck, Austria., pp. 037008, Sep, 2008.
Link: http://iopscience.iop.org/1752-7163/2/3/037008/
Abstract
We present a novel method for real-time breath-gas analysis using mass-spectrometric techniques: buffered end-tidal (BET) on-line sampling. BET has several advantages over conventional direct on-line sampling where the subject inhales and exhales through a sampling tube. In our approach, a single exhalation is administered through a tailored tube in which the end-tidal fraction of the breath-gas sample is buffered. This increases sampling time by an order of magnitude to several seconds, improving signal quality and reducing the total measurement time per test subject. Furthermore, only one exhalation per minute is required for sampling and the test subject can otherwise maintain a normal breathing pattern, thereby reducing the risk of hyperventilation. To validate our new BET sampling method we conducted comparative measurements with direct on-line sampling using proton-transfer-reaction mass spectrometry. We find excellent agreement in measured acetone and acetonitrile concentrations. High variability observed in breath-by-breath isoprene concentrations is attributed to differences in exhalation depth and influences of hyperventilation on end-tidal concentrations.

Featured Articles

Download Contributions to the International Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications:

 

Selected PTR-MS related Reviews

F. Biasioli, C. Yeretzian, F. Gasperi, T. D. Märk: PTR-MS monitoring of VOCs and BVOCs in food science and technology, Trends in Analytical Chemistry 30 (7) (2011).
Link

J. de Gouw, C. Warneke, T. Karl, G. Eerdekens, C. van der Veen, R. Fall: Measurement of Volatile Organic Compounds in the Earth's Atmosphere using Proton-Transfer-Reaction Mass Spectrometry. Mass Spectrometry Reviews, 26 (2007), 223-257.
Link

W. Lindinger, A. Hansel, A. Jordan: Proton-transfer-reaction mass spectrometry (PTR–MS): on-line monitoring of volatile organic compounds at pptv levels, Chem. Soc. Rev. 27 (1998), 347-375.
Link

 

Lists with PTR-MS relevant publications of the University of Innsbruck can be found here: Atmospheric and indoor air chemistry, IMR, Environmental Physics and Nano-Bio-Physics

 

Download the latest version of the IONICON publication database as BibTeX.